Powering And Surge Protection - Motorola BLE Series Installation And Operation Manual

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You can verify proper return alignment by injecting a carrier, at the design level, into any
amplifier at random. Proper alignment is achieved if you observe the reference level at the
headend optical receiver output.
Return levels used for alignment are not necessarily operational system levels. These levels
vary from system to system due to differences in equipment, architectures and design
philosophies. For an in-depth analysis and discussion of the return path, refer to Motorola
reference guide Return Path Level Selection, Setup and Alignment Procedure.
P o w e r i n g a n d S u r g e P r o t e c t i o n
In conventional applications, the line extenders are powered through the input port. To avoid
damage to the hybrids, it is recommended that you remove the input pad (JXP-IN) before you
apply power to the BLE*/*. A 20-ampere, blade-type fuse is furnished in the amplifier module
and provides overcurrent protection for ac power applied to the input. You can power the
BLE*/* from the output without passing power through to the input port. To block power from
the input port, remove the power-block jumper illustrated in Figure 2-9.
W A R N I N G !
To avoid possible injury to personnel or damage to the equipment, remove 60/90 volt ac power from
the system before you remove any components from the housing.
The BLE*/* is shipped from the factory configured for 38 through 90 Vac powering as described
in Section 2, "Overview". To configure the line extender for 55 Vac through 90 Vac operation:
Remove the E-pack from the housing.
1
Remove the power-supply cover.
2
Move the / selector (jumper J1 on the power-supply board) from the
3
LO HI
Figure 2-6 illustrates the jumper location.
Re-install the power-supply cover and torque the screws to 10 to 12 in-lbs.
4
Re-install the E-pack in the housing and torque the hold-down bolts to 18 to 22 in-lbs.
5
Standard surge protection is provided in the power supply by a heavy-duty, 230-volt, gas
discharge surge protector. As an option, you can install the FTEC crowbar overvoltage protector.
The FTEC, which replaces the standard gas-discharge tube, has a firing potential of
approximately 245 volts.
To install the FTEC:
Remove the E-pack from the housing.
1
Remove the power-supply cover.
2
Remove the gas-tube surge protector, illustrated in Figure 2-6.
3
Replace it with the FTEC.
4
Re-install the power-supply cover and torque the screws to 10 to 12 in-lbs.
5
Re-install the E-pack in the housing and torque the hold-down bolts to 18 to 22 in-lbs.
6
B L E * / * I n s t a l l a t i o n a n d O p e r a t i o n M a n u a l
to position.
LO HI